Refresh styled widget palettes when switching themes and fix Windows install prefix

Author: Alex9001

.github/workflows/release.yml

@@ -62,7 +62,7 @@ jobs:
         shell: bash
         run: |
           for scale in 1 2; do
-            QT_SCALE_FACTOR="$scale" TODOBENCH_THEME_SCREENSHOTS="$PWD/build/screenshots/$scale" build/release/test_main_window themesRender
+            QT_SCALE_FACTOR="$scale" TODOBENCH_THEME_SCREENSHOTS="$PWD/build/screenshots/$scale" build/release/test_main_window themesRender themeSwitchUpdatesExistingWidgets
           done
       - if: runner.os == 'Linux'
         name: Linux packages

native/src/app/theme.cpp

@@ -5,6 +5,7 @@
 #include <QRegularExpression>
 #include <QStyle>
 #include <QStyleFactory>
+#include <QWidget>
 #include <algorithm>
 #include <cmath>
 
@@ -165,11 +166,19 @@ QPalette theme_palette(const std::string& id, const ColorOverrides& overrides, c
 void apply_theme(const Settings& settings) {
     const auto& system = system_appearance();
     const auto& overrides = theme_overrides(settings);
+    // Qt stylesheet styles cache resolved widget palettes. Unpolish them before
+    // changing the application palette, then resolve their rules against it again.
+    std::vector<std::pair<QWidget*, QString>> stylesheets;
+    for (auto* widget : QApplication::allWidgets()) {
+        if (!widget->styleSheet().isEmpty()) stylesheets.emplace_back(widget, widget->styleSheet());
+    }
+    for (const auto& [widget, sheet] : stylesheets) widget->setStyleSheet({});
     const auto style_name = settings.theme == "system" && overrides.empty() ? system.style : QString("fusion");
     if (QApplication::style()->objectName().compare(style_name, Qt::CaseInsensitive) != 0) {
         if (auto* style = QStyleFactory::create(style_name)) QApplication::setStyle(style);
     }
     QApplication::setPalette(theme_palette(settings.theme, overrides, system.palette));
+    for (const auto& [widget, sheet] : stylesheets) widget->setStyleSheet(sheet);
 }
 
 double color_contrast(const QColor& foreground, const QColor& background) {

native/tests/test_main_window.cpp

@@ -46,6 +46,7 @@ private slots:
     void projectFilterNamesSurviveEditingAndTabSwitching();
     void themesRender_data();
     void themesRender();
+    void themeSwitchUpdatesExistingWidgets();
     void cancelThemeCustomizationPreservesSettings();
     void sampleWorkflowRenders_data();
     void sampleWorkflowRenders();
@@ -192,6 +193,53 @@ void MainWindowTest::newWorkspaceUsesSelectedFolder_data() {
     QTest::newRow("tutorial") << true;
 }
 
+namespace {
+void select_theme(MainWindow& window, const char* preset) {
+    for (auto* action : window.findChildren<QAction*>()) {
+        if (action->data().toString() == preset && action->isCheckable()) action->trigger();
+    }
+    QApplication::processEvents();
+}
+
+bool widgets_match_theme(MainWindow& window, const char* preset) {
+    const auto expected = theme_palette(preset, {}, system_theme_palette());
+    auto* filter = window.findChild<QLineEdit*>("taskFilter");
+    return filter->palette().color(QPalette::Base) == expected.color(QPalette::Base)
+        && filter->palette().color(QPalette::Text) == expected.color(QPalette::Text)
+        && window.findChild<QStackedWidget*>("detailStack")->palette().color(QPalette::WindowText) == expected.color(QPalette::WindowText)
+        && window.findChild<QTextEdit*>()->palette().color(QPalette::Base) == expected.color(QPalette::Base);
+}
+}
+
+void MainWindowTest::themeSwitchUpdatesExistingWidgets() {
+    QTemporaryDir temporary;
+    const auto root = std::filesystem::path(temporary.path().toStdString()) / "theme-switch";
+    QVERIFY(seed_task(root));
+    {
+        MainWindow window;
+        window.open_workspace(root);
+        window.resize(1280, 820);
+        auto* tree = window.findChild<QTreeView*>("taskTree");
+        tree->setCurrentIndex(tree->model()->index(0, 0));
+        window.show();
+        for (const auto* preset : {"brown", "light", "brown", "rose", "light"}) {
+            select_theme(window, preset);
+            QVERIFY(widgets_match_theme(window, preset));
+        }
+        const auto directory = qEnvironmentVariable("TODOBENCH_THEME_SCREENSHOTS");
+        if (!directory.isEmpty()) {
+            std::filesystem::create_directories(directory.toStdString());
+            QVERIFY(window.grab().save(directory + "/switched-light.png"));
+        }
+    }
+    QCOMPARE(std::get<Settings>(load_settings(root / "settings.json")).theme, std::string("light"));
+    MainWindow reopened;
+    reopened.open_workspace(root);
+    reopened.show();
+    QApplication::processEvents();
+    QVERIFY(widgets_match_theme(reopened, "light"));
+}
+
 void MainWindowTest::newWorkspaceUsesSelectedFolder() {
     QFETCH(bool, tutorial);
     QTemporaryDir temporary;

scripts/package-windows.ps1

@@ -16,7 +16,7 @@ if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
 cmake --build $BuildDirectory --parallel
 if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
 
-$Stage = Join-Path $BuildDirectory "windows-stage"
+$Stage = [System.IO.Path]::GetFullPath((Join-Path $BuildDirectory "windows-stage"))
 if (Test-Path $Stage) { Remove-Item -Recurse -Force $Stage }
 cmake --install $BuildDirectory --prefix $Stage
 if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }